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<h1>KEA</h1>

<p>Starting with GDAL 2.0, GDAL can read, create and update files in the KEA format, through the libkea library.</p>

<p>KEA is an image file format, named after the New Zealand bird, that provides a full implementation
of the GDAL data model and is implemented within a HDF5 file. A software library, likea, is used
to access the file format. The format has comparable performance with existing formats while
producing smaller file sizes and is already within active use for a number of projects within
Landcare Research, New Zealand, and the wider community.<p>

<p>The KEA format supports the following features of the GDAL data model:
<ul>
<li>Multiple-band support, with possible different datatypes. Bands can be added to an existing dataset with AddBand() API</li>
<li>Image blocking support</li>
<li>Reading, creation and update of data of image blocks</li>
<li>Affine geotransform, WKT projection, GCP</li>
<li>Metadata at dataset and band level</li>
<li>Per-band description</li>
<li>Per-band nodata and color interpretation</li>
<li>Per-band color table</li>
<li>Per-band RAT (Raster Attribute Table) of arbitrary size</li>
<li>Internal overviews and mask bands</li>
</ul>
</li>

<h2>Creation options</h2>

<p>The following creation options are available. Some are rather esoteric and
should rarely be specified, unless the user has good knowledge of the working
of the underlying HDF5 format.</p>

<ul>
<li><p><b>IMAGEBLOCKSIZE</b>=integer_value: The size of each block for image data. Defaults to 256</li>
<li><p><b>ATTBLOCKSIZE</b>=integer_value: The size of each block for attribute data. Defaults to 1000</li>
<li><p><b>MDC_NELMTS</b>=integer_value: Number of elements in the meta data cache. Defaults to 0. See the <a href="http://www.hdfgroup.org/HDF5/doc/H5.user/Caching.html">Data caching</a> page of HDF5 documentation.</li>
<li><p><b>RDCC_NELMTS</b>=integer_value: Number of elements in the raw data chunk cache. Defaults to 512. See the <a href="http://www.hdfgroup.org/HDF5/doc/H5.user/Caching.html">Data caching</a> page of HDF5 documentation.</li>
<li><p><b>RDCC_NBYTES</b>=integer_value: Total size of the raw data chunk cache, in bytes. Defaults to 1048576. See the <a href="http://www.hdfgroup.org/HDF5/doc/H5.user/Caching.html">Data caching</a> page of HDF5 documentation.</li>
<li><p><b>RDCC_W0</b>=floating_point_value between 0 and 1: Preemption policy. Defaults to 0.75. See the <a href="http://www.hdfgroup.org/HDF5/doc/H5.user/Caching.html">Data caching</a> page of HDF5 documentation.</li>
<li><p><b>SIEVE_BUF</b>=integer_value: Sets the maximum size of the data sieve buffer. Defaults to 65536.  See <a href="http://www.hdfgroup.org/HDF5/doc/RM/RM_H5P.html#Property-SetSieveBufSize">H5Pset_sieve_buf_size()</a> documentation</li>
<li><p><b>META_BLOCKSIZE</b>=integer_value: Sets the minimum size of metadata block allocations. Defaults to 2048. See <a href="http://www.hdfgroup.org/HDF5/doc/RM/RM_H5P.html#Property-SetMetaBlockSize">H5Pset_meta_block_size()</a> documentation</li>
<li><p><b>DEFLATE</b>=integer_value: Compression level between 0 (no compression) to 9 (max compression). Defaults to 1</li>
<li><p><b>THEMATIC</b>=YES/NO: If YES then all bands are set to thematic. Defaults to NO</li>
</ul>

<h2>See Also:</h2>

<ul>
<li><a href="https://bitbucket.org/chchrsc/kealib">libkea bitbucket repository</a></li>
<li><a href="http://www.sciencedirect.com/science/article/pii/S0098300413001015">The KEAimage file format, by Peter Bunting and Sam Gillingham, published in Computers&amp;Geosciences</a></li>
<li><a href="frmt_hdf5">HDF5 driver page</a></li>
</ul>

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